I could have sworn John Williams' "Appalachian Morning" used to be part of the pre-show. Am I thinking pre-RoE?
"Appalachian Morning" was the final song in the first RoE pre-show music loop that ran from RoE's introduction in 1999 until July 3, 2004. On July 4, 2004 they switched to the current pre-show music.
The original music was barely more than 30 minutes long (the MP3 I have is 31:39). Appalacian Spring starts at the 29:00 mark, so you usually didn't get to hear the whole thing.
The problem came when they had technical issues and had to delay the start of the show. When they ran out of music, I think it looped back to the beginning of the playlist. They fixed this problem with the new music, which runs almost 45-minutes. So they have some extra in case of any delays (or at least 15-minutes worth of delays) before having to repeat songs.
But, of course, this means that there are some songs in the pre-show playlist that most people never get to hear because they're not at a delayed-start show.
Here's the full list:
http://www.disneymusicloops.com/wdw/wdwepcot-ws-roe2.html
Typically, the show starts just after the 7th track, "Bear" has started. So you only hear a little bit of it, and rarely hear "Red Skies" or "Texas".
(I like "Red Skies", and think it should be moved up in the playlist to play more often... "Texas" is a little...weird. No other word for it)
-Rob